Recently, reduction in size, weight, and power consumption of electronic apparatuses and increase in capacity of batteries have driven increase of battery-driven electronic apparatuses. Further, in a short distance, operation modes in which data communication is made by wireless between apparatuses are increasing. Under these circumstances, the noncontact transmission technique is also needed for power transmission of the apparatuses.
An existing noncontact charging system, as disclosed in Japanese Unexamined Patent Application Publication No. 2008-206327, for example, is configured of a power transmitting unit having a primary coil installed on a charging platform or the like and a mobile electronic apparatus having a secondary coil and a rechargeable battery. In the stated charging system, a user places the mobile electronic apparatus upon the power transmitting unit. Through this, the primary coil of the power transmitting unit and the secondary coil of the mobile electronic apparatus form electromagnetic induction coupling (magnetic field coupling) therebetween so as to supply power to the side of the apparatus to be charged, whereby the secondary battery is charged.